Transfusion Therapy Flashcards
What makes the ideal canine blood donor?
Friendly, clinically healthy, over 25kg (not overweight), easily accessible veins, between 1.5-8 years
What makes the ideal feline blood donor?
Friendly, clinically healthy, over 4.5kg (not overweight), 1.5-8 years, indoor
What other factors are important for both feline and canine donors?
No history of travel abroad so have no blood borne disease, no transfusion themselves so no antibodies against RBC antigens, up to date with vaccination and worming
What tests should be performed before an animal donates for the first time?
Full biochemistry and haematology
What tests should be performed each time before an animal donates?
Thorough clinical exam to check health
PCV and total protein
Not within 14 days of vaccination
Cats tested for FeLV, FIV and Mycoplasma felis
How much blood is taken from animals?
About 15-20% of estimated blood volume?
What is the estimated blood volume of dogs?
80-90ml/kg
What is the estimated blood volume of cats?
55-65ml/kg
What is the canine donation procedure?
12 hour fast, pre-donation examination, clip 1 inch over jugular and prepare aseptically, needle through skin and release clamp, start phlebotomy, collect 405-480g whole blood agitating the bag every 50-75g, pressure over venepuncture site for 2-5minutes then wrap and observe for 15-30 minutes
What is the feline donation procedure?
12 hour fast, pre-donation examination, prepare equipment, place IV catheter and administer sedation, clip and aseptically prepare, position cat, raise vein and insert needle, assistant gently aspirate blood, gently rotate syringe during collection, pressure over venepuncture site for 2-5 minutes, wrap and observe for 15-30 minutes, administer 5ml/kg/hr IVFT for 3 hours
What equipment is need for feline blood donation?
IV catheter, sedation, 1 60ml syringe/3x20ml syringes with 1ml CPDA for ever 7ml of blood to be collected, sterile preparation for jugular, butterfly needle attached to anti-coagulant syringe, 2 assistants
What position should cats be in to donate blood?
Lateral recumbency or held in sternal with head up
What are blood groups determined by?
Proteins on RBC membrane
What are the canine blood groups?
DEA (Dog Erythrocyte Antigen) 1,3,4,5,7 commonly recognised blood groups and dogs can be positive for any DEA in any combination
Which DEA is most sensitive to sensitisation?
DEA 1 with antibodies formed within 1-2 weeks of transfusion
What happens if DEA-1 antibodies are formed?
Delayed haemolysis of the transfusion and if the dog receives another DEA-1 transfusion then an acute haemolytic transfusion reaction will occur
Are antibodies made against other DEAs?
Yes but reactions tend to be less severe so those blood groups aren’t tested for
What are the feline blood groups?
Cats can be type A, B or AB
What is different about RBC antibodies in cats than dogs?
Cats have naturally occurring alloantibodies to the blood proteins they don’t have with reactions being peracute and sometimes fatal to B type cats receiving A or AB type
What are the signs of type A or DEA-1 transfusion reaction?
Fever, icterus and destruction of transfused cells withing 24 hours
How is blood typing performed?
Generally a card system or in-house ELISA typing system and test for DEA-1 and type A and B
ELISA less subjective
When is cross-matching required?
Recipient has been transfused more than 4 days previously, history of a transfusion reaction, recipients transfusion history is unknown
What does the minor cross match test for?
Donor antibodies to recipient erythrocyte antigen
What does the major cross match test for?
Recipient antibodies to donor erythrocyte antigen
What temperatures are cross matches performed at?
37, 25 and 4C
What method can be used to test for cross matching in an emergency?
Testing for agglutination by taking serum and EDTA sample from recipient and donor, centrifuge for 5 mins then separate, wash EDTA RBC, have four slides for donor control, major CM, minor CM and recipient control, rock slides for 2 minutes, look for agglutination
What is put on each of the slides?
Donor control = 2 drops donor serum, one drop donor RBC
Major CM = 2 drops recipients serum, 1 drop donor RBC
Minor CM = 2 drops donor serum, 1 drop recipient RBC
Recipient control = 2 drops recipient serum, 1 drop recipient RBC
Why are blood products used?
Can replace exactly what they are missing and so seem a more appropriate fluid, however, natural products are variable so reactions aren’t uncommon
Why should anti-coagulated blood products not be administered with fluids which contain calcium?
Can result in formation of calcium salts and microthrombi
What is the most common blood product used in practice setting?
Fresh whole blood
What is fresh whole blood ideal for?
Patient that has undergone substantial acute haemorrhage
What should be used if not immediately available to resuscitate patients?
Crystalloid or colloid therapy
How much fresh blood is needed to raise the PCV?
2ml of fresh blood raises recipient PCV by 1%